Core C will serve renal investigators in several areas: 1. Pathology. 2. Cell Biology. 3. Plasma assays. 4. Magnetic resonance imaging (MRI). For Pathology and Cell Biology, we provide infrastructure, equipment, service, and education on all standard techniques but we remain flexible for innovative and novel procedures as the need arises. We will provide a service for a much needed plasma Klotho assay for the renal research community which is unique at the moment. We will also offer a non-invasive way of quantifying renal fibrosis in vivo in rodents with MR imaging. The service component will be partially supported by a cost-recovery scheme. We will devote some resources and use the O'Brien Center as a platform for discovery. We will develop a state-of-the-art proximity ligation assay (PLA; high sensitivity specificity and throughput) first for Klotho, then FGF23, and finally other biomarkers of interest in renal disease as a Renal PLA Panel. On the MRI front, we will explore various novel functional MRI techniques in both rodents and humans to lay a foundation database for further refinement of functional MRI techniques in renal research. This Core works within the mission of the O'Brien Center to promote and faciliate renal research by providing key services and education. In addition, we will bring together the diverse interest and expertise of renal investigators to jump-start and catalyze scientists from outside disciplines to bring the latest technology and expertise into renal research.